Method for production of fabrics



June 9, 1942. v. R. HARDY METHOD FOR PRODUCTION OF FABRICS Filed Aug.22, 1940 .INVENTOR ATTORN EY Patented June 9, 1942 METHOD FOR PRODUCTIONOF FABRICS Vernal B. Hardy, Wilmington, DeL, minor to E. L du Pont deNemours & Company,

Wilmington, DeL, a corporation of Delaware Application August 22, 1940,Serial No. 353,692

6 Claims.

This invention relates to the cold-drawing of fiat fabrics woven fromsynthetic linear polyamide yarns in order to form three-l 'yarn, cuttingthe fabric into pieces of substantially the outline shape of the articleto be produced and forming or shaping the fabric by coldarticles such asbrassires and also foundation garments, girdles, and the like.

The standard brassiere fabric of the art is woven or knitted fromcotton, rayon, or silk yarn.

The fabric must be cut to shape, then sewn. seaming is usually necessaryIt is sometimes desirable to laminate these fabrics. These variousoperations in the production of brassieres result in a high cost offabrication, the production of objectionable seams and ridges,unsatisfactory fit, and distorting and stretching in service.

Attempts have been made to form three-dimensional articles from flatfabrics composed of cellulose derivative yarns. Cellulose derivativefabrics, for example, cellulose acetate fabrics may be shaped and formedinto the desired three-dimensional article by incorporating a suitablequantity of a plasticizer or softening agent in the fabric, or byheating the fabric until it is plastic, prior to the shaping operation.Articles formed in this manner from cellulose derivative fabrics aregenerally unsatisfactory. Such articles often exhibit a loss of fabricidentity which results fromthe pressing together of the highlyplasticized yarn and the lack of flexibility in the resultant fabric.Other fabrics produced in this manner often exhibit an objectionableopening of the fabric. Quite recently yarns have been produced from anew class of materials known as synthetic linear polyamides. Thepreparation of this material and the formation of yarn therefrom aredescribed in U. S. Patents Nos. 2,071,250; 2,130,523 and 2,130,948. Theterm synthetic linear polyamide, as used throughout the specificationand claims, is intended to refer specifically to the material disclosedin the above-identified patents.

Synthetic linear polyamide yarns can be "colddrawn to greatly increasetheir tenacity and lower their elongation. Before weaving syntheticlinear polyamide yarns, they are customarily cold-drawn 150% to 500% oftheir original length to impart the requisite physical propertiesthereto.

It is an object of the present invention to form, by cold-drawing,three-dimensional articles from fiat fabrics woven from synthetic linearpolyamide yarns, which articles ar characterized by their well-shapedform, great strength, and retention of fabric identity.

Other objects of the invention will appear hereinafter.

The objects of the invention may be accomplished by weaving a flatfabric from undrawn, or partially-drawn, synthetic linear polyamidedrawing the same into the three-dimensional form of the desired article.The three-dimensional drawn fabric article may then be substantiallypermanently set by treatment, with a hot, (i. e., at a temperature of C.to C.), wet,

non-solvent sweling agent for the polyamide, as

described in U. S. Patents Nos. 2,157,117 or The nature of the inventionwill become more clearly apparent by reference to the following detaileddescription when taken in connection with the accompanyingillustrations, in which:

Figure l is a perspective view of a shaping device suitable for use inshaping three-dimensional articles in accordance with this invention.

Figure 2 is a perspective view of a finished brassiere produced byshaping in accordance with this invention.

Figure 3 illustrates a section of specially constructed fabric for usein accordance with the present invention.

Referring to Figure 1 of the drawing, reference numeral l0 designates,generally, a base of a cold-drawing apparatus suitable for use inaccordance with the present invention. A fabric clamping element I2 isfixed to the base member III. The fabric clamping element l2 contains apair of openings ll which are adapted to cooperate with a pair ofcold-drawing dies hereinafter to be referred to. A second clampingmember I is pivoted to the fixed clamping member 12, The pivotedclamping member I4 is provided with a pair of lugs 20 which are adaptedto cooperate with a pivoted thumbs'crew l8 attached to the fixedclamping member. The synthetic linear polyamide fabric is clampedbetween the two clamping members so as to project over the two openingsH as illustrated. A colddrawing member 22 is hinged to the supportingbase I adjacent the side of fixed clamping member l2 opposite to theside on which clamping member 14 is pivoted. The member 22 is providedwith a pair of cold-drawn forming dies 24. The forming dies 24, uponswinging the member 22 into contact with the fixed member l2, areadapted to fit within the openings l1, thereby forcing, andcold-drawing, the fabric l6 overlying the openings I'l into athree-dimensional shape. The hinged member 22 may be swung intocold-drawing position by means of handle 26. In the apparatusillustrated in Figure l, the cold-drawn dies 24 are in the shape of cupsto form a brassiere of the fabric clamped between clamping members l2and i4.

Referring to Figure 2 of the drawing, reference numeral 30 designates apiece of fabric having the general outline of a brassire. The fabwoveninto the fabric as filling yarns.

ric has been cold-drawn to form therein two cups 32. The brassire isconstructed from the fabric 30 by merely attaching the necessary strapsand fastening elements. I

Figure 3 of the drawing illustrates a specially woven fabric which isparticularly adapted for use in accordance with the present invention.

In this modification of the invention, a fabric is woven primarily ofyarns 40 which are incapable of being cold-drawn. These yarns may bepreviously cold-drawn synthetic linear polyamide yams or they mayconsist of yams: composed of other materials. A plurality of undrawn, orpartially drawn, synthetic linear polamide yarns 42 is woven into thefabric as warp threads and a similar plurality of undrawn, or partiallydrawn, synthetic linear polyamide yarns 42' is These undrawn yarns,which are designated by heavier lines in the drawing, are adapted tooverlap each other leaving a central overlapping section designated bynumeral 44 which is constituted entirely of undrawn, or partially drawn,synthetic linear polyamide yarns. The cold-draw which is to be appliedto the fabric will be applied at this section which contains onlyundrawn yarns.

The following examples are illustrative of specific methods for theproduction of brassieres in accordance with the present invention. Theinvention is, of course, not to be limited by the specific details ofthese examples,

Example I A fiat fabric having 50 warp and 60 filling threads per inchand woven from 160-denier, 70- fllament, -turn per inch, undrawnpolyhexamethylene adipamide yarn is made into pieces of the properoutline and dimensions of a brassire. A piece of this fabric is tightlyclamped between clamping elements such as members l2 and ll of Figure l.The sections of the fabric overlying the openings I! are then cold-drawnby swinging draw plate. 22 into its upward position against the clampingplate l2 so that the cold-drawn dies 24 are moved through the openingsl1 against the fabric I6. After the sections of the fabric have beencold-drawn as above outlined the clamping elements are released and thefabric is removed and placed upon a form having the general outline of acompleted brassire and is there subjected to a hot, wet settingtreatment in a manner similar to that described in U. S. Patent No.2,157,117. The fabricis then converted into a brassiere as shown inFigure 2 by stitching around the edges and attaching the necessarystraps and fastening elements thereto. The brassiere may then be dyedwith dyes usually utilized for the dyeing of cellulose acetate and isgiven a final boarding treatment on a suitable form in a manner wellknown in the art. Cutting of the fabric before or after the colddrawingmay be accomplished in various ways, as, for example, with a rotarycutter. A heated cutter or a hot blade may be used to obtain a weldedselvage.

Example II A flat fabric having 50 warp and 50 filling threads per inchand woven from 170-denier, 60- filament, 4 -turn per inch, undrawnpolyhexamethylene adipamide yarn is made into pieces of the'same generaloutline as a brassire. A piece of. this fabric is cold-drawn by theapparatus shown in Figure 1 in a method as outlined in Example I. Incarrying out the process in acfastening elements to the brassire.

cordance with this example, the clamping elements l2 and I4 are slightlyreleased and saturated steam is passed between the two clamping elementsto contact the drawn sections of the fabric for a period of two minutes.The fabric is then removed from the drawing apparatus and is fashionedinto-a brassire by stitching around the edges of the fabric andattaching straps and The brassire is then dyed in a hot dye bath and isgiven a final boarding-treatment on a suitable form,

The brassieres prepared in the examples are well-shaped, are verystrong, and stillpossess their fabric identity. They retain their shapeover long periods of wearing despite exposure to considerable stressesbecause the setting treatment so increases the force'required to drawthe fabric that for all practical purposes the set fabric isnon-drawable by the forces to which it is ordinarily exposed in thecourse of its everyday use.

Although the invention has been discussed with respect to thepreparation of a brassiere, it is to be understood that other shapedarticles may be prepared in accordance with the principles of theinvention; e. g., foundation gar ments, combination brassires andgirdles or even hats, gloves and many other three-dimensional articlesmay be prepared by cold-drawing fabrics prepared from undrawn, orpartially drawn, polyamide yarn.

The invention may be carried out with the aid of many different types ofcold-drawing devices. For example, an expanding device such as aninflatable rubber form may be used to produce such shaped fabrics asgloves, and the like. Also, polyamide fabrics may be embossed withvarious designs by subjecting the undrawn fabric to pressure between apair of suitably cooperating embossing rolls. 1

Various types of novelty fabrics may be prepared in accordance with thisinvention. Un-

.drawn polyamide yarn may be plied with viscose rayon, cellulose acetaterayon, cotton, or

other yarns; the plied yarn may then be converted into a fabric and thefabric may be colddrawn to such an extent as to break the latter yarn oryarns to produce-a novel fabric.

Various types of mixed fabrics may be made in accordance with thisinvention with an undrawn polyamide yarn only in the warp and some otheryarn in the filling; or similarly, the polyamide yarn may be presentonly in the filling while some other yarn constitutes the warp. Thus afabric may be produced which is drawable in one direction only. Also. itis possible to use polyamide yarns which have been coated with anessentially non-drawable material in the production of novel fabrics;upon drawing the fabric, the coating is broken producing novel effects.

The invention has been discussed with respect to fabrics woven fromundrawn yarns or partially drawn yarns. Polyamide yarns, as customarilyused in the weaving of fabrics, are cold-drawn from about 150% (1.5:1ratio of drawn to undrawn yarn) to about 500% (5:1 ratio of drawn toundrawn yarn) before the yarn is fabricated. In accordance with thepresent invention very good results may be obtained by cold-drawingsections of fabrics which are woven from partially drawn syntheticlinear polyamide yarns, for example, yarn which has been drawn from toNovelty fabrics may be prepared by fabricating yarns which have beenpartially drawn to different extents the various sections of the yarn,then cold-drawing the fabric in accordance with the present invention,dyeing and finishing. Furthermore, noveleffects may be obtained byspinning a low viscosity polyamide, weaving it into fabrics and drawingthe finished fabrics so that the threads will crimp. Since the fabricsmade from yarns which have been partially drawn, it is to be understoodthat the invention covers the cold-drawing of any fabric prepared from ayarn which is capable of being cold-drawn.

Various types of setting treatments may be applied to the shaped fabricsof this invention;

e. g., steam, setting, setting with alkali sulfite solution, etc.; orthe fabric may be left unset, if desired.

Yarns prepared from other filament-forming synthetic linear polymerswhich are capable of being cold-drawn may be used in accordance with thepresent invention; for example, synthetic linear interpolymers,synthetic linear vinyl polymers and vinyl interpolymers, syntheticlinear polyesters, polyesters, polyacetals, and interpolymers of two ormore specific polymers of the same type or of different types of theabovenamed polymers may be used to advantage.

These yarns may contain or may be treated with various modifying agents,such as lustermodifying agents, plasticizers, wetting agents,

swelling agents, pigments and dyes, anti-oxidants, resins, sizingagents, finishing agents, etc.

This invention makes possible new, improved shaped articlescharacterized by great durability,

desirable elastic properties, and good appear-' ance. Brassieres andother shaped articles can be produced which conform more closely to theshape desired than similar articles heretofore available. A much morecomfortable article of clothing is produced by reason of the eliminationof most of the seams which are necessarily pres ent in a brassiere madeby sewing together several pieces of fabric. Much labor is saved in theproduction of brassieres by eliminating the steps of cutting numerouspieces of fabric, fitting these pieces together, and sewing them.Moreover, the process of this invention is more economical than theprior art processes, of molding thermoplastic materials by reason of theelimination of the requirements for heat, swelling agents, andplasticizing agents. Cold-drawing requires none of these; but it is tobe-understood that it may be desirable at times to use plasticizingagents or swelling agents or heat and such modifications lie within thescope of the present invention. Preference for the cold-drawingprocedure has been expressed because of the simplicity and low cost ofsuch a procedure as compared with a hotdrawing procedure. However, sincenumerous synthetic linear polyamides are capable of being drawn atelevated temperatures, it will be ob vious that the invention is not tobe limited to cold-drawing. In certain cases drawing in a hot, wetatmosphere may be highly advantageous because lower forces are requiredto draw polyamides in such an atmosphere.

The discovery that dyes usually utilized for dyeing cellulose acetateare particularly suitable for dyeing p lyamide yarns and fabrics helpsto make these yarns more useful in the practice of this invention; forthese very effectively cover up differences in denier and extent ofdrawprinciple of this invention may be applied to sult of the inventionis the increase in wrinkle resistance that accompanies the cold-drawingof the synthetic linear polyamide fabrics .in accord ance with thisinvention.

As it is evident that many changes and modifications can be made in theabove-described details without departing from the nature andspirit ofthe invention, it is tobe-understood that the invention is not to belimited to the abovedescribed details except as set forth in theappended claims.

I claim:

1. The process which comprisescold-drawing, into a three-dimensionalarticle, a fiat "fabric woven from synthetic linear polyamide yarn whichis capable of being cold-drawn.

2. The process .which comprises cold-drawing, into a three-dimensionalarticle, a fiat fabric woven from synthetic linear polyamide yarn whichis capable of being cold-drawn, and imparting a substantially permanentset to said cold-drawn article by subjecting the same at atemperature-of C. to C., to a non-sol vent swelling agent for thepolyamide.

3. The process which comprises tautly clamping a fiat fabric having atleast one section containing synthetic linear polyamide yarn which iscapable of being cold-drawn and at least one section in which the yarnis incapable of being cold-drawn, and cold-drawing, into athree-dimensional form, that section of the fabric containing thecold-drawable yarn.

4. The process which comprises tautly clamping a fiat fabric having atleast one section containing synthetic linear polyamide yarn which iscapable of being cold-drawn and at least one section in which the yarnis incapable of being cold-drawn, cold-drawing, into a three-dimensionalform, that section of the fabric containing the cold-drawable yarn, andimparting a.

substantially permanent set to said cold-drawn section by subjecting thesame, at a temperature of 85 C. to 150 C., to a non-solvent swellingagent for the polyamide.

5. The process which comprises tautly clamping a fiat fabric having atleast one section in which both the warp and filling are composed ofsynthetic linear polyamide yarn which is capable of being cold-drawn andat least one sec-- tion in which the yarn is incapable of beingcolddrawn, and cold-drawing, into a three-dimensional form, that sectionof the fabric in which both the warp and filling is composed of thecolddrawable yarn.

6. The process which comprises tautly clamping a fiat fabric having atleast one section in which both the warp and filling are composed ofsynthetic linear polyamide yarn which is capable of being cold-drawn andat least one section in which the yarn is incapable of being colddrawn,cold-drawing into a three-dimensional form, that section of the fabricin which the warp and filling is composed of cold-drawable yarn, andimparting a substantially permanent set to said cold-drawn section bysubjecting the same,

at a temperature of 85 C. to 150 C., to a non- CERTIFI M'E 0FCORRECTION. Patent No. 2,285,967. June 9, 191 2.

- VERNAL R. HARDY.

It is hereby certified that error appears izi the printed specificationof the above numbered patent requiring cerrectien as fellows: Page l,sec- 0nd column, 'line 9, for "sweling'! read -,-SW111I18--; lines 14.6and 51 ;0 "cold-drawn" read co1d-d.raw--; I page 3, first column, lihe25, for "polyesters" second occurrepce, read poly ethera and that thesaid Letters Patent should beread with this correctioh therein that theI fonn to the record of the case in the Patent Office.

Signed and sealed this 2131: (m of Ju1y,-A; D. 1912.

same may con- 7 Henry Van Arssdale (Seal) Acting Commissioner ofPatents.

